Support for electric heating elements and method of making same



Dec. 31, 1940. a A. RUTENBER 2,226,781

SUPPORT FOR ELECTRIC HEATING ELEMENTS AND METHOD OF MAKING SAME FiledSept. 21, 1939 2 Sheets-Sheet 1 INVENTOR ATTORNEY E. A. RuTENBEr Dec.31, 1940.

SUPPORT FOR ELECTRIC HEATING ELEMENTS AND METHOD OF MAKING SAME FiledSept. 21, 1939 2 Sheets-Sheet 2 & BY Edwin E! FzzZenZen N INVENTOR ATTORNE Y L DC: 5;

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wW a? Patented Dec. 31, 1940 UNITED STATES SUPPORT FOR. ELECTRIC HEATINGELE- MENTS AND METHOD or MAKING SAME Edwin A. Rutenber, Greenville,Mich, assignor to Gibson Electric Refrigerator Corporation, Greenville,Mich., a corporation of Michigan Application September 21, 1939, SerialNo. 295,899

5 Claims.

This invention relates to electric heating element supports and theprocesses for making them.

It is an object of this invention to provide a simple and economicallymanufactured onepiece support for electric heating elements. Anotherobject of the invention is to provide a novel method of making aone-piece heating element support from a single flat sheet of metal.

These objects are attained by providing a single rectangular sheet ofmetal, punching a plurality of holes inthe metal sheet which arearranged in transverse rows and longitudinal columns, the transverserows being grouped in pairs with a wider space between the pairs of rowsthan between the rows in each pair, folding the metal along transverselines between the two rows of holes in each pair of rows to provide aplurality of longitudinally spaced apart V-sliaped channels which have asingle row of holes in each leg thereof, and installing insulators ineach longitudinally aligned pair of openings in the opposite legs ofeach channel.

In order to provide for heat transfer and circulation of air,transversely extending rows of holes are formed in the-webs whichconnect ad jacent channels. Preferably, all the holes are formed in theflat sheet before it is folded as described above.

For a more detailed description of the inven-- tion reference is made tothe following specification and the accompanying drawings, wherein:

Figure l is a bottom plan view of an oven heating unit embodying thisinvention;

Figure 2 is a top plan view of the unit shown in Figure l;

Figure 3 is a fragmentary sectional view taken on substantially the line3-3 of Figure 2;

Figure 4 is a fragmentary sectional view aken on substantially the line4-4 of Figure 2;

Figure 5 is a plan view of a sheet metal blank from which the supportfor the heating element is fashioned; and

Figure 6 is a side elevational view of the heating element support afterit has been folded and bent to final shape.

The present invention is shown as embodied in the heating unit for anoven of an electric range. The unit comprises a heating element supportIn carrying insulators ii to hold the heating coils ll, i2 and ii; aframe 25 and 28 of channel shaped cross-section surrounding theinvention particularly relates is the support in for the heatingelements. It comprises a plurality of downwardly extending transverselyarranged V-shaped channels l5, separated from each other by webs it. Atthe opposite ends of the support In are downwardly extending flanges 2Band 2|, the latter having an opening 22 therein.

Each channel is provided with a row of openings il in each leg thereof.Each opening in each leg of each channel is arranged in longitudinalalignment with an opening in every other. leg of all the channels.

The webs it of the support ID are provided with rows of openings IE topermit heat generated by the heating elements to radiate and circulatefreely throughout the oven. Preferably the openings it are larger thanthe openings [1,

although it will be obvious that the openings l6 may be made of anydesired size.

In each pair of aligned openings in the opposite legs of each channel I!are insulators iii. The insulators have ribs l9 intermediate their endspositioned between the legs of the channels I5 to prevent removal of theformer from the openings ll. In each insulator is an opening l8a for thereception of a heating element. The heating elements ll, l2 and I3 abovementioned are threaded through the openings Na in the insulators in themanner indicated in Figure 1, and their ends are brought out adjacentthe flange 2|.

The edges of the support III are embraced by a frame composed of strips25 and 26 of channel shaped cross-section. The side flanges of the strip25 are notched at 21 and the latter is bent into U-shape (see Figures 1and 2). The other strip 28 of the frame has its flanges cut away at theends, and the web 28 which remains is bent at right angles to thecentral part of the strip and is joined in overlapping relation to theweb of the strip 25.

The two strips 25 and 26 are held together by the ends 80 of a pair ofhangers 29 formed from metal rods bent to the shape shown in Figures 1to 4.- The ends are threaded and inserted in openings in the overlappingwebs 25 and 26 and secured there by nuts 32. The other ends ll of thehangers are secured solely to the web of the strip 25 by nuts 33.

Secured in the opening 22 of the flange 2|, and a complementary opening3! in the strip 28 is a terminal block 24 composed of insulatingmaterial. The block 24 carries four terminal plugs 35, 36, 31 and 38which are adapted for insertion in sockets at the back of the oven inorder to make Proper connection with a suitable source of electriccurrent. The inner ends of the terminal plugs are secured to the ends ofthe heating coils or heating elements II, I: and iii, in the mannershown in Figure 1.

The support Hl previously described is formed from a single sheet metalblank of the shape shown in Figure 5, which is stamped in a suitablepunch press to provide a series of transversely extending rows ofopenings l6 and Il. The openings ii are larger than the openings ll. Theopenings ll are equi-distantly spaced in the rows. The rows of openingsI! are arranged in pairs with a row of openings it between each pair ofrows of openings IT. Preferably two rows of openings l1 and one row ofopenings l6 are formed in one operation of the press, although it willbe apparent that by the use of suitable dies all of the openings may beformed at one time. When the openings are punched three rows at a timethe blank is moved the requisite distance after each operation of thepress and the punching operation is repeated until the required numberof rows of openings are formed. In addition, the opening 22 is formed inone end of the blank while the latter is in the flat state.

After the openings l8, l1 and 22 are punched in the blank, it is foldedalong the lines marked I, 8 and 9 into the cross-sectional shape shownin Figure 6 and previously described. The bottoms of the channels l5 areformed by bending the blank along the fold lines I, while the apices ofthe angles between the legs of the channels it: and the intermediatewebs H are formed along the fold lines 8. The end flanges 20 and 2! areformed by bending the ends of the blank along the lines 9.

By folding the blank in the manner just described each opening I! ineach row is aligned with a corresponding opening in each 01' the otherrows so that in the finished support the channels l5 are pierced by aseries of longitudinally aligned openingsextending the length of thesupport. The openings l6 are thus located in the webs ll intermediatethe channels IS.

The blank I II comprises metal of suillcient flexibility that it may beflexed after the channels l5 have been formed to permit the insertion ofthe insulators Hi. When the frame is attached to the support III theinsulators I! are permanently locked in place. After the insulators I8have been placed in the support and the support has been attached to theframe, the heating coils are threaded into the openings IS in theinsulators. a

From the foregoing it -will be seen that the invention provides a sturdyand rigid support for the heating elements of an electric oven, andbecause it is made in one piece from a single sheet of metal the supportis easily fabricated and assembled.

The scope of the invention is indicated in the.

ing their ends projecting through the respective openings in theopposite side walls.

2. In an electric heating unit, a one piece support for an electricheating element comprising a plurality of V-shaped channels havingflexible side walls arranged in parallel relation and connected byhorizontal coplanar webs, opposite side walls of each channel havingpairs of aligned unconnected openings therethrough, and a tubularinsulator in each pair of openings, said insulators having radial ribsintermediate their ends positioned between the channel side walls andhaving their ends projecting through the respective openings in theopposite side walls.

3. The method of making a one piece support for electric heatingelements, which includes the steps of providing a substantiallyrectangular blank of flexible metal, forming therein a plurality ofspaced transversely extending pairs of rows of openings, said openingsbeing of ,equal ment with the corresponding row in the other leg,thereafter flexing the legs ofthe V-shaped channels apart, installing aninsulator in each aligned pair of openings in the opposite legs of eachchannel, and finally returning the legs of the channel to their initialpositions.

4. The method of making a one piece support for electric heatingelements, which includes the steps of providing a substantiallyrectangular blank of flexible metal, forming therein a plurality ofspaced transversely extending pairs of rows of openings, said openingsbeing of equal size and equi-distantly spaced in the rows, the spacebetween the adjacent pairs of rows being greater than the space betweenthe rows in each pair, folding the blank intermediate the rows of eachpair of rows whereby to form a plurality of parallel V-shaped channelshaving a row of I openings in each leg thereof arranged in alignmentwith the corresponding row in the other leg, thereafter flexing the legsof the V-shaped channels apart, installing a tubular insulator having aradial rib intermediate its ends in each aligned pair of openings in theopposite legs of each channel with the rib between the legs of therespective channel, and finally returning the legs of the channels totheir initial positions.

5. The method of making a one piece support for electric heatingelements, which includes the steps of providing a substantiallyrectangular blank of flexible metal, forming therein a plurality ofspaced transversely extending pairs of rows of openings, said openingsbeing of equal size and equi-distantly spaced in the rows, folding theblank intermediate the rows of each pair of rows whereby to form aplurality of parallel V-shaped channels having a row of openings in eachleg thereof arranged in alignment with the corresponding row in theother leg, thereafter flexing the legs of the V-shaped channels apart,installing an insulator in each aligned pair of openings in the oppositelegs of each channel,

and finallyreturning the legs of the channel to 7 their initialpositions.

EDWIN A. RU'I'ENBER.

